1. Field of the Invention
The present invention relates generally to the field of sod harvesters, and more specifically, to a sod harvester with a flap control device for consistently and neatly rolling pieces of sod so that the end of the flap is situated at roughly the same position on each roll of sod.
2. Description of the Related Art
Sod harvesters for cutting strips of sod from the ground, rolling them into sod rolls, and stacking the sod rolls onto pallets have existed for a number of years. Various sod harvester innovations have been patented, several of which relate to the rolling of sod pieces, and at least one of which has attempted to solve the same problem as the present invention. U.S. Pat. No. 7,021,584 discloses a sod roller for automatically controlling the angular position of the end or flap of a roll of sod about the roll. The latter invention differs structurally from the present invention in a number of respects, including, but not limited to, the fact that it utilizes three conveyors rather than two, and it also incorporates a sensor for measuring displacement of the transport conveyor. The transport conveyor sensor is not needed in the present invention.
When sod is sold at commercial establishments, it is typically stacked several rows high on a pallet. The more neatly the stack appears, the more likely it is to be sold. In addition, neatly stacked rolls are less likely to fall off of the pallet. In both of these respects, the placement of the end of the flap on the sod roll is important. If the end of the flap is located at roughly the same position on each of the sod rolls, this creates a more uniform appearance and adds stability to the overall configuration of the sod rolls. The present invention is designed to ensure that the end of the flap on a roll of sod is situated at roughly the same position on each roll of sod that comes off of the sod harvester.
Other innovations relating to sod rollers include U.S. Pat. No. 3,790,096 (Brouwer, 1974) (device for starting a turn in the end of a sod strip); U.S. Pat. No. 4,142,691 (Watton, 1979) (apparatus for starting a turn in a strip of sod travelling along a conveyor); U.S. Pat. No. 6,834,729 (Brouwer et al., 2004) (pre-starter for starting a turn in the end of a sod strip travelling up a conveyor); and U.S. Patent Application No. 2001/0050174 (Van Vuuren) (in one embodiment, incorporating a rolling conveyor between the receiving and discharge ends of the conveyor head for purposes of rolling cut grass sods). None of these innovations, however, is concerned with the consistent positioning of the end of the flap on the sod roll.